Check code base for UTF-16

[chrisjsewell]

@chrisjsewell can you think of any other places in the codebase where this Javascript string (string of UTF-16 code units) versus Python3 string (string of Unicode codepoints) difference could cause issues.

I just realized we unintentionally fixed one instance of this in #70 😄 The old entity data seemed to contain UTF-16 code units.

Originally posted by @hukkinj1 in #81 (comment)

[hukkin]

https://github.com/tsutsu3/uc.micro-py seems like a place where an error like this might have slipped in.